Interior conduit



' Nn. 607,989. Patented July 26, |898.

E. E. & F. W. ERICKSON.

INTERIOR CUNDUIT.

N (Application filed June 3, 189B.) o Model.)

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ERIC E. ERICKSON AND FREDERICK W. ERICKSON, OF BOSTON, MASSACHUSETTS.

INTERIOR QCONDUIT.

SPECIFICATION forming part of Letters Patent NO. 607,989, dated. July 26, 1898.. Application filed Tune 3, 1898. Serial No. 682,457. (No model.)

To all whom t may concern:

Be it known that we, ERIC E. ERICKSON and FREDERICK W. ERICKSON, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Interior Conduite, of which the following is a speciication.

The present invention relates to improvements in interior-conduit systems, and es v pecially to the insulating terminals or thimbles and to the junction or outlet boxes associated therewith.

The improved conduits for buildings used at the present time consist of met-al pipes lined with paper or some other suitable insulating material, and where they terminate at an outlet it is desirable that their ends be tted with an insulating-thimble, as is fully explained and set forth in thePatent No. 566,507, granted August 25, 1896, to F.V W. Erickson, one of the parties to the present invention.

This invention describes an improved form of terminal end or thimble for interiorconduits, which is especially adapted tol be joined to the inside of the j unction-box at which it terminates and to constitute an insulated end for the conduit.

The invention also relates to an improved junction or outlet box as a new article of manufacture.

In all 4such boxes that we are aware of the walls are of considerable thickness, and the holes for the end of the conduit-pipes to enter are punched or drilled when the boxes are made, or else provision is made for breaking holes in their walls when they are about to be put in place by making ceiled openings or portions of the walls circular in form and thinner than the rest of the Walls, which portions can be knocked out when wanted for conduit-entrances. These methods possess many disadvantages, asconduits will vary in diameter according to the size or number of conductors it is proposed to extend through them to the j unction-box. It is not desirable to have openings which are larger than the conduits, and it is impossible to foretell the sizes Wanted until the box is to be set up.

Our invention consists of a box made of comparatively thin metal plate having its sides cut to shape and bent, as hereinafter described, to form lapping joints at the corners, which are riveted together and to a brace, whose upper end serves as a nutinto which a screw passes to hold the box-cover on. There are no orifices in the walls of the box, and no provision is made for ceiled openings, but the walls are purposely made thin in order that openings can be punched therein of any diameter at any time by means of ordinary circular steel punches.

The invention provides certain other improvements in interior-conduit construction, which will be particularly described hereinafter.

Of the drawings, Figure l is a perspective View ot our improved outlet-box. Fig." 2 is a plan of a piece of sheet metal cut ready to be bent into shape. Fig. 3 is a top view of the box with its cover removed. Fig. 4 is a perspective view of a corner of the box. Fig. 5 is a section on line a: of Fig. 4.. Figs. 6 and 7 are perspective views of the insulatingthimble to be connected with the end of a conduit-pipe. Fig. S is a section of insulating-thimble, showing itsV connection with a conduit-pipe and a wall of the outlet-box. Fig. 9 is a plan view of an outlet-box in position in the wall of a building," and Eig. lO is a section on line y y of Fig. 9. p

To make the outlet-box, thin sheet metal of about No. 22 in thickness is cut into rectan gular pieces of sufficient length and width to include the distances across the bottom and the height of the sides. The corners are then cut out, as shown in Fig. 2, which represents a plate for a square box. The .sheet is prefer ably stamped out by a die, however. The parts are then turned on the dotted lines, the edges 3 turned over, the corners 2 are turned up, then the sides l are turned up at right angles. Holes 5 are punched in the corner edges 4, which are bent to lap over each other at an angle. 6 are metal braces lprovided with two lugs 7, extending from 'one side, and 1l is an angle-piece at its top, in which is a screwthread 8. The lugs 'Z are inserted in the holes 5 and riveted down. The tops of the angles 6 are a little below the edge 3 to form a ledge, upon which rests the cover 9, which is secured The cover is stamped from by the screws 13.

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a piece of metal plate and has an opening in its center surrounded by a flange 10.

The box as described is sold to the trade as an article of manufacture, and when it is to be used in any place the openings for the conduit-pipes are punched out to suit the exigencies of the case.

Referring to Figs. 6, 7, and 8, A represents an insulating-terminal for a conduit-pipe,consisting of a metal memberj andan insulating member 't'. The member j consists of a ring a, joined to an internally-threaded sleeve d by a thin flange c, forming a circular depression or channel h between them. The sleeve d is preferably longer than the ring a to obtain sufficient length of screw-thread. L is a ring of insulation, which may be turned from a solid block to fit into the channel h and upon the end of the member j, but is preferably molded upon the member while in a soft state and then hardened. Its outer end is rounded, as shown, and has a straight lip g, extending inwardly from the outer end of the sleeve d, for a purpose to be hereinafter explained. This insulating-terminal constitutes an article of manufacture and is made of several diameters to fit standard sizes of metal pipes.

In the fitting of buildings for electric lighting the interior conduits are, as is well known, run inside the walls and partitions and are brought to outlet-boxes, as shown at Bin Figs. 9 and lO, the box being entirely inclosed by the plastering C, the conduits D entering the boxes, so that the insulated wires can be brought to the electric-light xture or be carried through another conduit to another box.

The manner of connecting our improved box and insulating thimble with an interiorly-insulated metal conduit is shown by Figs. 8, 9, and 10. As the box has no openings for conduits after the size and -location of the conduits for the particular place has been determined the holes therefor are punched by means of steel dies. The outer surfaces of the conduit ends are threaded and a nut m screwed on. Then the conduit ends are inserted into the openings of the box and the insulating-thimble A screwed onto its end. The nut fm is so adjusted on the conduit to the outside surface of' the side of the box that the end of the conduit will come about iiush with the outer end of the sleeve d of the thimble A, so that when the latter is screwed up the insulating-lip g will about meet the insulation of the conduit or so nearly that there will be no chance for a bare electric conductor to touch the metal pipe. The design is to make a close connection between the insulation of the thimble A and of the insulation of the conduit. In the figures we have shown several sizes of conduits entering the'box B.

With this improved box the exact-sized hole wanted is made and in the exact position desired, both very important considerations in the fittings for electric conducting apparatus of this character. We consider it important that an insulatingthimble that is to be screwed upon the end of a conduit should have its thread in metal and that the surface which bears upon the inner surface of the box should also be metal and also that as much as possible of the metal constituting the thimble should be covered with solid insulation in preference to insulating paint or enamel, and so we have devised the form shown, in which these ideas are carried out.

We claim as our inventionl. In interior-conduit systems, an outletbox having its bottom and sides formed from a single piece of thin metal sheet or plate, cut at its corners to provide lapping joints; with a metal brace riveted to each of the lapping joints@ having a screw-thread in its upper end; and a metal cover havin g a central opening surrounded by an outwardly-projecting Harige, as set forth.

2. In interior-conduit systems, an outletbox having its bottom and sides formed from a single piece of thin metal sheet or plate, cut at its corners to provide a double-rolled edge for the sides, and lapping corner-joints; with a metal brace riveted to each of the lapping joints having a screwthread in its upper end; and a metal cover having a central opening surrounded by an outwardly-projecting flange, as set forth.

3. In interior-conduit systems, an outletbox having its bottom and sides formed from a single piece of thin'metal sheet or plate, cut at its corners to provide lapping joints; with a metal brace riveted at each corner to the lapping joints by means of lugs integral therewith, the upper part thereof being screwthreaded; and a metal cover having a central opening surrounded by an outwardly-projecting flange, as set forth.

4. In interior-conduit systems, an outlet-insulator consisting of an internally-threaded metal member composed of two rings of different lengths and different diameters united by a thin ange or web, and an insulating member fitting over the ends of the rings, and into the channel between them, and extending inward as a lip, as set forth.

5. In interior-conduit systems, an outlet-insulator consisting of an internally-threaded metal member composed of two rings united by a iiange or web, and an insulating member fitting over the ends of the rings, and into the channel between them, and extending inwardly from the end of the inner ring, as set forth.

6. In interior-conduit systems, an outlet-insulator consisting of an internally-threaded metal member composed of a disk from one side of which extends two rings of different diameters; and an insulating member fitting over the ends of the rings and into the channel between them, as set forth.

7 In interior-conduit systems, an outlet-insulator consisting of an internally-threaded metal member composed of a disk from one IOO IIO

side of which extend two rings of dierent diameters; and an insulating member fitting over the ends of the rings and into the channel between them, and extending inward from the end of the smaller ring, as set forth.

8. In an interior-conduit system, the combination of an outlet-box, and of an outlet-insulator consisting of an internally-threaded metal member composed of two rings united by a flange or web, and an insulating member fitting over the ends of the rings and into the channel between them, and extending inwardly from the end of the inner ring; with an interior Cond uit or pipe having an insulat-` ing-lining, as set forth.

9. In an interior-conduit system ,the combination of an outlet-box, and of an outlet-insulator consisting of an internally-threaded metal member composed of a disk from one side of which extend two rings of different diameters; and an insulating member fitting over the ends of the rings and into the channel between them; with an interior conduit or pipe, having an insulating-lining, as set forth.

10. In an interior-conduitsystem, the combination of an outlet-box having its bottom and sides formed from a single piece of thin metal sheet or plate, cut at its corners to provide lapping joints; having a metal brace riveted to each of the joints with a screw-thread in its upper end; and a metal cover having a central opening adapted to be secured to top of the box; and of an outlet-insulator consisting of an internally-threaded metal member composed of a disk from one side of which extend two rings; and an insulating member tting over the ends of the rings and into the channel between them;- with an interior conduit or pipe having an insulating-lining, as set forth.

. In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses/this 2d day of June,

ERIC E. ERICKSON.l FREDERICK W. ERICKSON. Witnesses:

WILLIAM P. CROCKETT, GEO. WILLIS PIERCE. 

